Will your EV catch fire?
Very few EV manufacturers will tell you this! Have a look on this quick article before buying your electric vehicle. Smartphones catching fire has become a common news these days! And we know that it happens because of Lithium batteries. Lithium batteries are used in electric vehicles too! You may want to spend couple of minutes here to understand about your safety.
Future is electric. Wether it is with lithium batteries, hydrogen cells, graphene cells, super capacitors, Aluminium-air batteries, or any new technology. Currently other technologies are still in nascent stage, and lithium batteries rule the EV market and may not get replaced anytime soon for two wheelers. Because two wheelers require small size, light weight and cost effective batteries.
For most of us, two wheelers are just a medium of transportation and not an aspiration. Switching to electric will not impact our commute patterns such as range anxiety with cars. Most people use two-wheelers within city and not beyond 100-150 km in a day. Hence this article is focused on electric two wheelers, in very simple language for basic understanding.
Why Lithium batteries of vehicles catch fire?
- Short Answer: Thermal Runaway. Short circuits within cell.
- Short circuit within the cell is very rare. Manufacturers have found better methods to pack the chemicals in a way that they don’t short-circuit.
- While vehicle is cruising, battery generates ample amount of power which creates heat within the battery cells. Similarly, while charging, heat is generated. Combined with atmospheric temperature, when temperature & heat within the battery exceeds certain levels, chemicals within battery become unstable. In more simple words, Heat generated through high temperature ignites the battery chemicals. Just like we ignited paper, cotton or match stick using magnifier glass in the sunlight in childhood.
- To prevent this, a cut-off circuit (BMS) is used which keeps an eye on temperature, current and voltage and cuts-off the power if required. But if this circuit malfunctions, it can create hazards.
All Lithium batteries catch fire?
- Short Answer: No. Certain types are more prone to catch fire than others.
- There are different types of lithium batteries depending upon battery chemisty. Mostly NMC, NCA, type lithium batteries are more prone to catch fire. Where as LTO, LFP batteries are considered safer. To know more about these types, click here.
How to prevent such high temperature rise?
- Short Answer: Deploy appropriate cooling methods.
- Temperature rise / Heat generation depends on various technical factors like peak power of vehicle, max speed, voltage, etc. Lesser the peak power, lesser the heat generation. Higher the voltage, lesser the heat generation due to Less amperes.
- Liquid cooling, Air cooing or gel based filler medium is used to dissipate heat generated during cruising or charging. Air cooling is less efficient than other two methods. NMC and NCA batteries which are more prone to catch fire should be designed thoughtfully with better cooling methods for higher factor of safety.
Verdict: For two wheelers, one should not fear much about fire hazard. Safety measures are already taken by OEM itself. Opting for safer battery type is in user’s control. Moreover such batteries give longer usage life. To know more about battery types, click here.